Keissleriella was introduced by Von Höhnel (1919) and is characterized by ascomata with an ostiolar neck covered by short dark setae (Liu et al. 2015; Ariyawansa et al. 2015b; Singtripop et al. 2015). Although sequence data for the type species K. aesculi (Höhn.) Höhn. are unavailable, many authors accept Keissleriella in Lentitheciaceae (Zhang et al.2009; Hyde et al. 2013; Ariyawansa et al. 2015b; Singtripopet al. 2015), based on available sequence data and morphololgy. Our specimen (MFLU14–0597) shows typical characteristics of Keissleriella, such as short brown setae around the apex of ascomatal ostiole and cylindro-clavate asci with hyaline, 1-septate ascospores (Barr 1990; Zhang et al. 2012), but differs from other Keissleriella species in having immersed ascomata under a blackened clypeus. Hence, we introduce a new species K. tamaricicola considering both morphology and phylogeny.